Clarify the matter of “memory”

Editor’s note: This article comes from WeChat public account “Mr. L said” (ID: lxianshengmiao ) , author: Lachel. Many students often ask me: Why is your memory so good? Is there any way to improve memory? Today, I want to talk about this issue. Of course, learning and memory are a huge topic. This article is just a first look. I hope to help you open up some horizons and clear up some confusion.

01

First, let’s take a look at the brain’s first memory system.

As we all know, memory systems can be roughly divided into short-term memory and long-term memory. Short-term memory is equivalent to “memory”, and long-term memory is equivalent to “hard disk.” When we receive any piece of information, we must first put it into short-term memory so that the brain “recognizes it” before it can be written into long-term memory and let the brain “remember” it.

That is, how much we can remember depends on how much information ends up in long-term memory.

But the brain has a huge disadvantage compared to computers: Our long-term memory can be huge, but the capacity of short-term memory is pitifully small.

How many? Everyone must have heard “7 + -2”-this is the data of the last century. In fact, according to the 2001 Cowan study, the more accurate data is: 4 units.

What is 4 units? In simple terms, it is 4 words, or 4 phrases. In other words, when you read the previous paragraph, your brain is busy doing many things: breaking a sentence into several phrases, first putting 4 into short-term memory, identifying them; then clearing, re- Squeeze 4 phrases in and recognize. Back and forth.

The problem here is: Recognition is much faster than “memory”. In other words, after these 4 phrases are recognized by you, they may not be able to form a memory, they will be immediately cleared out to welcome the new 4 phrases.

What did you get in the process? You actually get nothing. A large amount of information is cleared during this “entering → leaving” process, and it cannot be “remembered” by the brain. All you get is just a series of “I see!”The moment.

For example, it’s like a thief, sneaking into a castle to steal something, grabbing a bunch of treasures and stuffing it into a pocket, but he has a big hole in the pocket, and he still doesn’t know-what is the result How about it? How many plugs leak. The only thing left is “there is treasure here” “there is also here!” “They are all mine!” “False ecstasy”.

So, why do we read a lot of books and articles and feel “good spoken” when reading them, but ca n’t make much impression after reading? This is why.

So how do we get the treasure we stole-no, it is the information that can be read that can be retained to the maximum and written into long-term memory from short-term memory? We need to study the next system.

02

Think about it: What did you eat last night?

This question is not difficult. I believe most people can answer it immediately. If not, then … you may have too much in your head, please relax yourself.

So, one more question: What did you eat on Wednesday night last week?

I believe there are not many friends who can answer this question.

So why can I recall what I ate last night; but what I ate last Wednesday can’t be remembered? Here, “What did you eat last night”, is it short-term memory or long-term memory?

Obviously, it is long-term memory. Because the short-term memory information will be continuously erased, and can only be held for a few seconds to tens of seconds.

But even long-term memory is complicated. In long-term memory, there is a buffer area called “Fresh Living Area”. It refers to the information that has been written into long-term memory in the recent period of time.

How long is this “recent period”? It varies from person to person, and there is no clear research result, but it is generally considered to be more than 6 hours and less than 1 day.

Information within the living area can be “remembered” effortlessly. But once the information leaves the living area, it is difficult to recall.

So, combining these two systems, we now have such a model: Information → short-term memory → long-term memory(Fresh area) → Real long-term memory

Next, let’s look at their neural basis.

03

We always say “memory” and “storage” … but is there something in the brain, like the computer’s memory and hard disk, dedicated to storing data?

There is no such thing.

In our cerebral cortex, there are about 16 billion neurons. All memories are characterized by these 16 billion neurons.

How do you characterize it? Each neuron can be connected to other neurons. And these 16 billion neurons, their “connection state” state, every moment is different. When you read the previous paragraph, the neuron cluster A is in the A1 state; when you read the next sentence, the cluster A is in the A2 state … This is the essence of “storage memory”.

That is, what happens inside your brain when you recall the first paragraph? In essence, it is to let the neuron cluster A build the A1 state again.

This is a very interesting thing: the brain cannot “store” any information-it can store only the state of its own neurons when certain information is obtained. And The so-called “memory” is essentially “playback” out of this state.

Okay, after understanding this, let ’s see: What is the nature of short-term memory? It is to make a bunch of neurons temporarily connect to each other to form state A1.

What is the nature of long-term memory? It is to let this bunch of neurons, through long-term connection, produce chemical changes, let them “glue” together, and fix this A1 state-this is called Touch plasticity. ”

What about “fresh area”? It refers to a state in which these neurons are highly sensitive to each other, and it is particularly easy to “play back” A1; but at the same time, their “adhesiveness” is not strong enough to last long. Cure to form long-term memory.

Then why does the information in the live zone disappear after a while? Because the “high sensitivity” of these neurons disappeared. You can understand that they are left, and no one sticks them together, so they are cold, lose their sensitivity to each other, and become the same as before.

From here, you can actually get an inference: What is the nature of learning? In fact, it is through this “synaptic plasticity” that the structure of the brain is changed , thus having a new thinking mode.

That is to say, a very intelligent person may not have a large brain capacity and may not have any very special brain circuits, but his brain must have richer and more complex neurons than ordinary people. connection. It is these complex connections that allow his mind to move freely and without hindrance.

Learning a field, learning a series of knowledge, learning a skill … in essence, it’s all the same, all of which change the internal connection of the brain.

04

Here we can think about it.

When we say a person has a good memory, what do we mean? Under normal circumstances, there are two meanings: 1) What he has seen can be recounted almost without any omission. 2) He can recall information that he read a long time ago, and events that he experienced.

The first refers to the ability to effectively write information from short-term memory to long-term memory to avoid loss; the second refers to his rich and complete long-term memory so Easily “play back” a certain state.

Obviously, the second kind is based on the first kind-only long-term memory can be enriched continuously.

So, our question comes: how to develop the ability to “write information from short-term memory to long-term memory”?

Actually, there is an experimental method in the psychology community called “n-back test”.

What do you mean? For example: If you stare at a screen, numbers on the screen will constantly appear randomly from 1-9. All you have to do is look at the current number and compare it to the “previous n number”. If yes, press Yes; if no, press No.

For example, the number displayed on the screen is like this: … 1, 4, 3, 4, 2 …

Now, the number you see is 3, assuming n = 2, then, you need to think back, what is the first 2 number? It’s 1, not the same, so press No.

The next number is 4, you keep thinking back,What is the first 2 numbers? Yes 4, consistent, OK, press Yes.

The next number is 2, continue to recall, the first 2 numbers are 3, not consistent, press No …

Is it difficult? You know, n = 2 is the simplest case (there is also n = 1, which is “compared to a number”, which is more used in patients with cognitive impairment or memory impairment). Difficulty going up, there are n = 3, n = 4 …

Many studies have suggested that the n-back test can improve memory to a certain extent, and thus improve fluid intelligence. In many experiments, the n-back test is also often used to measure memory level: the fewer mistakes you make, the higher the number of correct answers, and the better your memory.

But do we have to use the n-back test to exercise memory in our daily life? Actually not. What we have to do is to explore the principle behind this simple method.

05

It is not difficult to find out, what is the principle of n-back test? In fact, it is “forcing” your brain to let it spend more energy to “hold” a piece of information in the short-term memory.

In short: since recognition is much faster than memory, and because of this, the information is cleared before it is “remembered”-then we artificially keep it longer One point, isn’t it effective in strengthening memory?

Make an analogy: you reach out and hold a handful of sand, what will happen to it? Will drain from your fingers. How can I take this handful of sand away? You have to close your fingers tightly, close your hands, and turn your hands into a closed space, “binding” the sand inside.

Similarly, how can a piece of information be remembered? You need to spend effort. Let the brain “pack and compress” a short piece of information into a short-term memory and process it.

How does it work? That ’s what I said before: Establish connections between neurons, and let this information “root” in your mind. This is called “fine processing”.

Use a process to say: “Pack and compress” a complex piece of information into short-term memory, focus on maintaining a period of time, and perform it during this time Fine processing, making as many connections as possible. So, to improve memory, there are two abilities to exercise:

1) The ability to compress and maintain a complex piece of information

2) The ability to make information more connected So, based on this principle, what kind of exercises can we do in ordinary life to exercise them? ?

Share a few easy ways.

1. “What did I just read?”

When I read and watch videos, I have a habit that has developed over many years: Every time I see a new paragraph, I ask myself: What have I read before?

This “new paragraph” may be a page or two, a subtitle, or a transition of a video, and so on.

What are the benefits of doing this? There are two points. One is to improve one’s ability to “pack and compress” so that short-term memory can hold more and more complex information. The other is to remind yourself that some information has been missed? Can I get them back?

Try it: When you read this, think back to the full text of this article and ask yourself: What does the article say? Can I repeat the previous idea?

Let the information go through the brain instead of letting it go-so that you can really absorb the information you have acquired into your own.

2. “What is its internal logic?”

When reading an article, a book, an interesting point, or a point of knowledge, I will let myself think about it: what is its internal logic?

What is internal logic? For example: if a point can be divided into three small points, I will not just remember these three small points, but I will think: What is the basis and standard for such a division? What is the principle and support of each point? Is it logically related to what I said before?

What’s the benefit of doing this? You don’t just stay at the level of “what is it?” You can understand from the deeper logic through the phenomenon: why is it like this?

In a nutshell, this can continuously establish the connection between knowledge points, transforming it from a simple tree structure into a dense, complex “network”.

Improving memory, never means to remember it forcibly, but to remember it through thorough understanding.

3. “What can I think of about it?”

When I come across some new knowledge, or a topic or topic, I will do some “rumination”. That is, temporarily shutting down external information input, and using this theme as an introduction, let yourself develop associations.

Why do you do this? On the one hand, it can activate those sleeping neuron nodes in the brain and wake them up again (refer to my The Iceberg of Cognition mentioned, The nature of the brain is a Bayesian model. We will have a probability judgment when facing all kinds of events in this world. This allows us to understand daily life more efficiently, and to avoid dangers and solve problems more effectively.

And memory is actually the feedback of this Bayesian model: we experience all kinds of events in daily life, Extract “information that the brain finds useful” and incorporate them In the model, it is used to improve the probability judgment and improve the probability database. -This information is memory.

Therefore, memory never needs to be restored 100%, because it is very sufficient now.

That ’s why I have always emphasized: The brain is used for thinking, not for memory.

But does this mean we “don’t need to remember” things? of course not. Its most accurate understanding iswhat? We don’t need to “force memory” things, but through the understanding of things, the characteristics and patterns of things are extracted and incorporated into our existing knowledge system.

In a nutshell, it is 8 words: outline outlines, dots and faces.

Do you need to remember the details of a complex theory? Need to remember that it can be subdivided into several points, and each point can be subdivided into several small points? No need. What you need to keep in mind is:

What characteristics does it have? Where is it in the entire system and framework? What types of questions might you need to think about? What is the connection with other issues and concepts? How can I call it?

Only by disassembling, restructuring, connecting, and weaving knowledge into a web, can you truly understand and remember them.

Similarly, this is the only way. When you need to start from a certain node, you can extract the entire knowledge network through the connection between the nodes.

This is the true “memory”. It is also a more valuable and effective “memory”.

I am the main one and I use it.

Everything you go through is really worthwhile only when they form “a part of you.”